What's happening to me?

I just joined this place so I'm sorry if I've placed this topic in the wrong place!
I've just turned sixteen and I feel like in all my days of being fifeteen I was being watched by a force. I know this sounds stupid but a lot of weird things have happened.
My first supernatural encounter was when I was twelve at camp. I was alone in a cabin while everyone was out & I was doing my hair. As I finished my hair I saw a woman in the corner of my eye, staring at me through the mirror. As soon as I turned around, nothing was there. Later that week when I returned home I told my mother about it and she just shook it off and told me I was imagining stuff. That night I was going through old photo albums and I saw the woman in a photo. I then confronted my mother and she said it was her sister that passed away a while ago ( I had never seen a photo of her before this).

But this past year weird things have been happening! My computer shuts down & turns on itself, repeating the Mac tune, my cats have begun hissing at the walls, and I feel like someone is hovering over me while I'm trying to sleep. BUT the scariest thing happened to me about four months ago. It was about 2am & I had just woken up to go to the toilet. Once I was done I walked out into the hallway & I saw a dark area. Being myself, I naturally thought that my eyes were just adjusting the the dark but then as soon as I walked through it I felt like something walked through me & I got thrown down the hallway, landing on my back quite hard. Being scared, I crawled back to my room & stayed under my blankets for the whole night.

Ever since these experiences I've slept with my cats because I believe evil spirits are scared of them. But I also feel like I've become somewhat vunerable. This past year I've been emotionally unstable and I have self harmed and coincidently all the things happening this year has started after the harming.